1. Field of the Invention:
This invention relates generally to damper devices and more particularly, it relates to a spring-loaded dampening actuator comprising a piston-cylinder combination in which the actuator causes an object desired to be moved to be gently pushed out at a dampened or controlled speed when activated and to be pushed in at an undampened high speed by means of a reduced force.
2. Description of the Prior Art:
Heretofore, attempts have been made in the prior art to provide damper devices for properly controlling or moderating an object such as, for example, a lid or the like in which the lid is caused to be opened from its closed position in a smooth manner and is returned to its closed position with a proper positive sensation. Such a prior art damper device is shown and described in U.S. Pat. No. 4,342,135 to Matsuo et al. wherein moderation of the lid movement is accomplished by means of damping oil functioning to slow the rotation of a roller. The roller is munted upon a rotary shaft which is disposed within a housing. In use, part of the roller 7 which is exposed outside of the housing 9 is dynamically meshed with an arcuate moving member 6 adapted to move in conjunction with the lid 3. Thus, the damping force can be applied smoothly to the lid movement in this manner.
In U.S. Pat. No. 4,542,810 to Shimbara, there is disclosed a damper device adapted to the reciprocation of sliders along rails so that, when the sliders move in one direction, the damper absorbs the motion of the sliders and causes the sliders to move at a reduced rate of speed. When the sliders move in the other direction, the damper in inactivated in order for the sliders to move at a higher rate of speed with a minimal force. In particular, the dampers 13 are each provided with a case 13a for containing oil or grease and having the damping means and an arm 13b extending rearwardly from the case toward the rear of the housing 2. The arm 13b is supported by means of holder 15. From the lateral side of the case 13a, there extends a shaft having a rotary toothed gear wheel 14 fixed thereon. The shaft is connected to means within the damper 13 adapted to have the rotation thereof braked by means of the oil or grease contained within the case 13a. In operation, during rearward movement of the sliders 10 the toothed wheels 14 do not constantly engage the rack gears 12 formed within the lateral partitions 3 of the housing 2 so as to effect a smooth insertion with minimal force. On the other hand, when the sliders 10 are pushed outwardly during their forward motion the toothed wheels are caused to be wedged against the rack gears 12 and thus rotate against the braking force of the dampers 13. Consequently, the unit case 1 is gently moved out of the housing 2 at a reduced rate of speed.
While the aforenoted prior art devices are satisfactorily operative, it is noted that all of the prior art damper devices suffer from the disadvantage that they require the use of damping oil contained within a cylinder or housing. As a result, these prior art devices are susceptible to the problem of hydraulic fluid leakage after years of use whereby such leakage can cause damage to the surrounding environment. Furthermore, these existing designs are constructed of numerous component parts which increase materials cost and time-consuming labor expenses in their manufacture and assembly. It would therefore be desirable to provide an improved dampening device which utilizes air as the dampening fluid rather than oil so as to overcome the problem of fluid leakage. It would also be expedient to provide an improved dampening device formed of a minimum number of component parts which has been traditionally unavailable, thereby reducing manufacturing and assembly costs.
The spring-loaded dampening actuator of the present invention represents an improvement over the dampening devices described above in the '135 and '810 patents.